<p>Use the <code>host</code> attribute to provide a hostname, or subdomain, in the form of a string. This segment of a route helps to ensure that the route is unique. If you do not provide a hostname, the URL for the app takes the form of <code>APP-NAME.DOMAIN</code>.</p>

<pre>
---
  ...
  host: my-app
</pre>

<p>The command line option that overrides this attribute is <code>-n</code>.</p>
